Change propane to electric?

kats_meowFebruary 26, 2010

We are buying a house (about 1900 SF in Texas) built 30 years ago. It has a Federal-Pacific panel of about 125 amps and at least one subpanel in the barn. The house is on propane for heat, cooktop, and water heater.

We plan to replace to electric panel which is also too small with some double taps.

We are wondering if it is feasible at the same time to put in 200 amps and convert from propane to electric, not sure what kind of cost would be involved.

It seemed like if we were at all interested in doing this we would do it now when replacing the panel.

Oh, also, there are no GFCI protected outlets and we would probably take care of that as well in the kitchen and bathrooms.

We can't tell you. First electrical labor rates vary highly and we don't know what people get in your area. Second, the power company will have to make changes to increase the service and the charges to do so vary with locale and the specific issues with regard to your site.

200A service wouldn't be a bad idea, especially if you're changing over to more electric appliances. I'm not sure why you'd do so, but that's a matter of taste. Certainly doing at the same time you replace the panel would make the most sense.

Adding GFCI protection is trivial (panel change or not).
Don't forget the garage (if at or below grade), unfinished basement, and outside receptacles if you really want to be compliant with the current code for such,

Propane will still be cheaper per BTU unit produced in much of the country. We can't say if that's the case for your area or not. YOu need to investigate both costs and compare to be able to be sure. If you're gonna change the home to all electrical, I'd do a 400 amp panel instead of a 200. Lots of homes are undersized at 200 these days with all the electrical demands of a modern home. 200 is probably OK if you decide to stay propane for the major heat producing systems and appliances.

I would carefully scrutinize the cost of electric heat and hot water vs. propane. Electric heat is notoriously inefficient. I live in Massachusetts, and electric heat is not very popular here. I imagine Texas has a shorter heating season, so it might be a viable option, but for most people, it is cheaper to heat with gas or oil.
There are some good things about electric heat, though. It's quiet, clean, and almost zero maintenance. You can put thermostats in each room to individually control temps in those areas. So, depending on the type of propane heating system, and the # of zones, you might even save money. Plus, you can probably sign up for a budget plan with your electric company, and have pretty consistent electric bills throughout the year. This may also be possible with your propane supplier.
The bottom line: Propane is much more efficient, but electric might be a good choice for some people!

Electric heat is 100% efficient. None of it is wasted going up the chimney.You can't get any better than that. It might not be the best dollar value though.
Actually, that's true of resistive heat. Heat pumps actually can do about 400%.

I suspect that the bigger issue in most of Texas is COOLING which is how you are going to size your power requirements.

> Electric heat is 100% efficient. None of it is wasted
> going up the chimney.

But the powerplant is not. The waste heat goes up the stack at the powerplant. That's one reason that electric heat always costs more to operate. A plant burning natural gas, after transmission losses, might deliver 20-30% of its energy to you, to turn into heat. However, a gas furnace will use 80% to 96% of the gas's energy to heat your_home. No contest. (I don't know where propane fits into this equation, however.)

That said, RN is spot on about the heat_pump. Not many have a COP (Coefficient of Performance; the ratio of heat it can produce per kWh compared to plain resistive heat) of 4, but 3.5 isn't uncommon. Conventional air heat_pumps are most efficient and economical where the climate is mild; their COP falls quite a bit as the outside temperature falls. If you have harsher winters consider a ground source heat_pump ("_geothermal") system.

A heat pump with propane auxiliary heating might make some sense, but I know the electric rates in TX have been increasing (thank you, George!). Switching from propane to electric HW probably doesn't make much sense. As to cooking, that's also up to you, but the retrofit of electric lines for stove/oven/cooktop would probably add up to a cost too great to pay for with any savings over time.

To be clear, I don't care if I get savings from this over time. I also don't care if propane is less expensive than electric.

I do care if the cost to convert is absurdly expensive. To be (I hope) extreme to make a point, if it was going to cost $50,000 to convert to electric I wouldn't do it. On the other hand if it was going to cost $5,000 I would do it.

The fuel cost afterwards is not that important. Where I live typically has mild winters. I much prefer electric cooktops (the oven is already electric, by the way). I just prefer electric to propane and if the cost to convert is not too much I want to do it even if my fuel costs go up.

There's all sorts of cost factors here. You're not talking about $50,000 most likely. Most of the labor is going to be replacing that panel. The big unknown is what the power company wants to upgrade the service. Of course you'll have to pull some stout wire up to where the cooktop would be (I'd seriously give a look to induction cooktop, it provides all the quick response/fine control of gas in a smooth, cool surface electric cooktop).

As for heat, you're probably ripe for an air-to-air heat pump (especially if the A/C is old or you don't have one and want to add it). You're talking a few thousand for the unit there.

The first thing you need to do is a demand load calculation. This will determine the size of service you require. If you go with standard water heater you might get by with 200 amp. If you are thinking tankless water heater then 200 amp is probably going to be too small. Those tankless heaters use 120 amps alone.

Is the demand load calculation something that the electrician could do? We probably are going with a tankless water heater due to space considerations. (Currently the water heater is not tankless and due to where it is the freezer door can only be opened halfway. There does not seem to be any good place to relocate the water heater but a tankless would fix the space problem.